1 There have been two process improvements implemented by the ABS in recent years which have improved the quality of data, with the biggest improvements seen in the external cause chapter and for coroner certified deaths. These processes were both implemented for the 2008 reference year. The first was a revisions process outlined in Explanatory Notes 35-39 and the second was in relation to the use of additional information stored within reports on the NCIS, see Explanatory Notes 63-73 for further information. The following technical note outlines the impact of the revisions process on 2006 data.

2 Previous publications of the Causes of Death, Australia indicated that all coroner certified deaths registered after 1 January 2007 are now subject to a revisions process. In order to improve the quality of historical data, the 2006 reference year data has also been revised as part of the Causes of Death, Australia, 2010 release. Therefore in the current release, 2006, 2007 and 2008 data is final, 2009 data is revised and 2010 data is preliminary. 2009 and 2010 data is subject to further revisions.

3 The process for revising the 2006 reference year was similar to the standard revisions methodology. Deaths that were reviewed were those that were open or unmatched at the time 2006 data were released. The difference between the process for 2006 and that for subsequent years, was that quality checks were run on all 2006 coroner certified records, not just those that were in scope for revisions. As a result, some additional records were reviewed and potentially revised. Specific codes that were targeted by quality checks included

records with unspecified codes (e.g. R99, X59, X84, Y09).

records with certain mechanisms and an intent of accident (e.g. W76 - accidental hanging and strangulation)

PRELIMINARY CODING

4 This section provides information on preliminary data for the 2006 and 2010 reference years.

5 The number of deaths coded to R99 (other ill-defined and unspecified causes of mortality) was higher in 2006 (930) than in 2010 (504). Similarly the number of deaths coded with unspecified mechanism (X59, X84, Y09) was higher in 2006 (384) than 2010 (93). Preliminary 2006 data was processed prior to the implementation of coding improvements.

6 The number of deaths with an undetermined intent was 0.1% for preliminary 2006 data (135) and 0.5% for 2010 preliminary data (680). Due to changes in coding rules for ICD-10 in 2007, processing of data up to and including the 2006 reference year assigned a finding of 'Undetermined intent' only where this was the official coronial finding. Other deaths where either intent was 'not known' or 'blank' on the NCIS record, were coded with an intent of 'accidental'.